15 research outputs found

    Report on the implementation of WorkPackage 2 "Analyses of legal, ethical, human, technical and social factors of ICT and e-learning development and intercultural competences state in every partner country" in the framework of the IRNet project

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    This article, prepared by an international team of researchers from different scientific areas, connected with ICT, e-learning, pedagogy, and other related disciplines, focuses on the objectives and some results of the international project IRNet. In particular, the article describes research tools, methods, and a procedure of the WP2, that is, analyses of legal, ethical, human, technical, and social factors of ICT and e-learning development, and the state of intercultural competences in partner countries: objectives, tasks, deliverables, and implementation of research trips. Researchers from Poland, the Netherlands, Spain, Slovakia, Portugal, Czech Republic, Australia, Ukraine, and Russia analyzed the results of WP2 in the context of the next stages and Work packages of IRNet project – International Research Network

    Report on the implementation of WP3 "Analyses and evaluation of the ICT level, e-learning and intercultural development in every participating country" in the framework of the IRNet project

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    This article, prepared by an international team of authors – researchers from different scientific areas, connected with ICT, e-learning, pedagogy, and other related disciplines – focuses on the objectives and some results of the IRNet international project. In particular, this article describes the research tools, methods and some procedures of the WP3 “Analyses and Evaluation of the ICT Level, E-learning and Intercultural Development in Every Participating Country”: Objectives, Tasks, Deliverables, and implementation of research trips. Except that, the article presents more important events, such as (video)conferences, seminars, workshops, an e-round table debate; among these events are ICTE2014, DLCC2014, “New Educational Strategies in Modern Information Space,” “Hightech information educational environment,” during which some more important results of the project research were presented. The list of publications includes 32 papers and a manuscript with WP3 results. Researchers from Poland, Russia, Ukraine, the Netherlands, Spain, Slovakia, Portugal, Czech Republic and Australia analysed the results of WP3 in the context of the next stages and Work packages of IRNet project – International Research Network

    Retrospective and real-time semiconductor dosimetry: applications to geological dating and brachytherapy quality assurance

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    In this thesis solid state semiconductor dosimetry is applied to the improvement of luminescence dating techniques (part 1) and quality assurance in high dose rate (HDR) brachytherapy (BT) cancer treatments (part 2). The aim of part 1 is the development, testing, and application of a novel method to measure spatially resolved dose rates in sediment samples using the Timepix pixelated detector. The Timepix contains an array of 256x256 pixels, each 55x55 μm in size and with its own preamplifier, discriminator and digital counter, and is able to provide the position and pixel-by-pixel count rate of the incident radiation. The development of a method to measure sediment samples and derive spatially resolved dose rates is described, followed by its application to sediment samples from Liang Bua and Denisova Cave archeological sites

    Deriving spatially resolved beta dose rates in sediment using the Timepix pixelated detector

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    Luminescence dating methods currently allow for the evaluation of the distribution of equivalent dose (De) values for individual sand-sized grains of quartz and feldspar from a given sample, but the environmental dose rate is still derived from the bulk sample. Additionally, single-grain optically stimulated luminescence (OSL) dating is performed on disaggregated samples, resulting in the loss of micro-stratigraphic context. To enhance the interpretation of De distributions, we aim to estimate the beta dose rate to sub-millimetre regions of intact samples using the Timepix pixelated semiconductor detector. The Timepix contains an array of 256 × 256 pixels, each 55 × 55 μm in size and with its own preamplifier, discriminator and digital counter. The detector has a total sensitive area of 1.98 cm2, and 65,536 independent channels. The output of each measurement is a matrix containing the position and pixel-by-pixel count rate (or deposited energy) of each particle that interacted in the sensitive volume of the detector. The main challenge in using the Timepix detector is low natural sample activity, and the goal of this work is to acquire data with minimal background contribution. With an experimental setup guided by Geant4 simulations, progress has been made to greatly reduce background noise using ad hoc shielding and post-acquisition particle analysis. We have established a Timepix measurement procedure applicable to resin-impregnated sediment samples, including sample preparation, measurement, and data processing and analysis. These steps have been tested on an artificial micro-stratified sample (composed of quartz and biotite grains held together by resin) to derive the corresponding spatially resolved beta dose rates

    Preliminary epi-diode characterization for HDR brachytherapy quality assurance

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    High Dose Rate vaginal brachytherapy for endometrial cancer has evolved from simple single-channel (i.e. cylindrical applicator) deliveries to treatments involving several channels (i.e. multichannel applicator) for the radiotherapy source to dwell, increasing the complexity of the dose distribution, and allowing more space for potential errors. For this reason real-time treatment verification has gained a greater importance than ever before, and more methods need to be developed in order to provide assurance that the dose delivery has been carried out as intended by the hospital staff. P-type silicon epi diodes have been designed at the Centre for Medical Radiation Physics (CMRP) in Australia to suit the specific needs of HDR BT, and characterized in the clinical BT facility of the Fondazione IRCCS (INT) in Italy. They have shown great potential for BT treatment verification in real time due to their radiation hardness, dose rate independence, flexibility in physical design, and ability to monitor the treatment at a 1-kHz readout frequency. Their dynamic range has been determined as ± 17 to ± 20 mm and dwell time calculation accuracy of \u3e 0.1 s has been shown. If placed on the same longitudinal plane of a treatment accessory, these detectors would enable coverage of about 40 mm for source position and dwell time tracking. Respective detector positioning at (0, +3, -3 mm) would extend this range to 45-50 mm, depending on the catheter location, proving to be sufficient for the majority of treatment cases. Further studies are encouraged to develop diodes with a wider dynamic range

    An innovative gynecological HDR brachytherapy applicator system for treatment delivery and real-time verification

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    The multichannel vaginal cylinder (MVC) applicator employed for gynecological high dose rate (HDR) brachytherapy increases dose delivery complexity, and thus makes the treatment more prone to errors. A quality assurance (QA) procedure tracking the source throughout dose delivery can detect dwell position and time errors in the multiple channels of the applicator. A new MVC system with integrated real time in vivo treatment delivery QA has been developed based on diodes embedded on the outer surface of the MVC. It has been pre-calibrated and verified using a non-clinical treatment plan with consecutive test positions and dwell times within each catheter, followed by the delivery of ten clinical plans of adjuvant vaginal cuff brachytherapy following hysterectomy for endometrial cancer. The non-clinical verification showed overall mean dwell position and time discrepancies between the nominal and measured treatment of −0.2 ± 0.5 mm and −0.1 ± 0.1 s (k = 1), respectively. The clinical plans showed mean positional discrepancies of 0.2 ± 0.4 and 0.0 ± 0.8 mm, for the central and peripheral catheters, respectively, and mean dwell time discrepancies of −0.1 ± 0.2 and −0.0 ± 0.1 s for central and peripheral catheters, respectively. The innovative prototype of the MVC system has shown the ability to track the source with sub-mm and sub-second accuracy, and demonstrated potential for its incorporation into the clinical routine

    An accurate method to quantify breathing-induced prostate motion for patients implanted with electromagnetic transponders

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    Purpose: To validate and apply a method for the quantification of breathing-induced prostate motion (BIPM) for patients treated with radiotherapy and implanted with electromagnetic transponders for prostate localization and tracking. Methods: For the analysis of electromagnetic transponder signal, dedicated software was developed and validated with a programmable breathing simulator phantom. The software was then applied to 1,132 radiotherapy fractions of 30 patients treated in supine position, and to a further 61 fractions of 2 patients treated in prone position. Results: Application of the software in phantom demonstrated reliability of the developed method in determining simulated breathing frequencies and amplitudes. For supine patients, the in vivo analysis of BIPM resulted in median (maximum) amplitudes of 0.10 mm (0.35 mm), 0.24 mm (0.66 mm), and 0.17 mm (0.61 mm) in the left-right (LR), cranio-caudal (CC), and anterior-posterior (AP) directions, respectively. Breathing frequency ranged between 7.73 and 29.43 breaths per minute. For prone patients, the ranges of the BIPM amplitudes were 0.1-0.5 mm, 0.5-1.3 mm, and 0.7-1.7 mm in the LR, CC, and AP directions, respectively. Conclusions: The developed method was able to detect the BIPM with sub-millimeter accuracy. While for patients treated in supine position the BIPM represents a reduced source of treatment uncertainty, for patients treated in prone position, it can be higher than 3 mm

    Applications of MOSkin dosimeters for quality assurance in gynecological HDR brachytherapy: An in-phantom feasibility study

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    In vivo dosimetry (IVD) is an excellent mode of treatment verification and detection of possible overexposures. A feasibility study was conducted to evaluate a proposed IVD procedure for gynecological HDR brachytherapy procedure quality assurance. MO. Skin dosimeters were selected due to their small size and capability of measuring steep dose gradients, such as those relevant in HDR brachytherapy procedures. Two in-phantom experiments measuring dose with MO. Skins at the position simulating the rectal wall were conducted employing a cylindrical single channel applicator and a multichannel applicator. Three MO. Skins were incorporated onto a rectal catheter, which was then attached to the applicator, separated by a small wooden plaque, simulating the vaginal to rectal wall distance and fixing catheter position. This setup was inserted into a water phantom and three treatment plans prescribing 300 cGy to 3 different targets were assigned with various dose distributions. Each treatment was administered three times, and doses measured by the MO. Skins were recorded. Doses measured by the MO. Skins were within 5% of the dose determined by the treatment planning system (TPS), ranging between 208 and 332 cGy, depending on dosimeter position on the rectal catheter. The overall average dose difference between measured and TPS values was 2.09% ± 1.15% (ranging between 0.83 and 4.27%, with measured values always higher than TPS dose), subdivided in 1.40 ± 0.37% and 2.79 ± 1.27% for single and multichannel applicator experiments, respectively. An overall dose agreement between the TPS and measured values, detector reproducibility, and practicality of the rectal catheter demonstrated the suitability of the proposed method for in vivo real time QA purposes in gynecological HDR brachytherapy
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